JW-Not sure if you got my post, so here goes. You asked the Question, how do you know how much gas to put in this Scottsman Ice maker unit. Well heres my answer......when viewing the frost from the evaporator, the FROST line should not go any further than the last coil out of the evaporator. From the last loop out of the evaporator, down to the suction port on the compressor........there should be NO frost from the evaporator to the compressor, period. In fact this POINT is used on ALL refrigerators, and Ice makers, so if there is no sticker with the amounts visible, just remember, frost to the end of the evaporator coil, but NO further. Brent@CanBC